1. Field of the Invention
The subject invention generally pertains to a heat exchanger and more specifically to a mounting structure that provides the heat exchanger with double vibration isolation.
2. Description of Related Art
A typical water-source heat pump includes a compressor that compresses and circulates refrigerant in series-flow through two heat exchangers and a flow restriction (e.g., an expansion valve). One heat exchanger transfers heat between the refrigerant and an external source of water (e.g., ground water). The other heat exchanger transfers heat between the refrigerant and a comfort zone, such as a room or other area within a building. Often a four-way valve determines whether the heat pump heats or cools the comfort zone by selectively directing the refrigerant flow in a forward or reverse direction.
Heat pumps are often, but not always, installed as a system of several heat pumps, where each individual heat pump serves its own particular zone within a building, such as an apartment unit, hotel room, dormitory room, or classroom. A network of pipes interconnecting the heat pumps typically conveys water to and from each individual unit. Each heat pump unit often has its own supply and return air duct for its particular comfort zone.
When heat pumps are installed as a system of several units, often the most convenient location to install the units, the water piping, and the air ducts is overhead, or above the ceiling of each comfort zone. With the heat pumps in such proximity with the comfort zones, it becomes important to minimize any noise generated by the heat pumps. Noise is primarily created by the components that have moving parts, such as the compressor and a blower that forces the conditioned air through the room.
To provide a cushioned mounting for blowers or to minimize noise created by a compressor, such components can be mounted using vibration isolators, such as rubber grommets. Examples of such isolators are shown in U.S. Pat. Nos. 2,711,285; 4,984,971; 5,839,295; and 5,306,121. Further isolation can be achieved by installing an intermediate mounting plate between the compressor and a stationary base, as shown in the '971, '295, and '121 patents.
However, in conventional heat pumps, the effectiveness of a high performance compressor isolation system can be compromised by vibration and/or pressure pulsations transmitted to auxiliary components in direct contact with the compressor. One such component is the water-to-refrigerant heat exchanger. Typically, these components are not isolation mounted. Vibration transmission from the compressor to the unit structure via these components can become the controlling factor in heat pump noise.